[Attached explant method for cell culture of human aortic smooth muscle].
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Adolescent↗
Biomedical subjects
Y Song
Publications and source records attributed to Y Song.
Enhancement of blood flow in experimental microvascular free flaps.
Prolonged ischemia may result in tissue death because of the no-reflow phenomenon. By raising a flap 24 hours prior to subjecting it to ischemia, the authors have been able to significantly lengthen the ischemia interval prior to the onset of tissue death. These effects are believed to be the result of alteration of the no-reflow phenomenon.
Animals↗
Ischemic induction of neovascularization: a study by fluorometric analysis.
The dynamic process of skin flap neovascularization can be quantitated in a relatively non-invasive fashion in an "in-vivo" model using the technique of perfusion fluorometry. The extent of skin flap ischemia can be monitored, and its effect on angiogenesis rapidly determined. Evidence is presented that indicates that angiogenesis develops from a distal to proximal direction corresponding to the degree of ischemia as measured by fluorescein uptake and elimination. Furthermore, although certain proximal segments of skin flaps demonstrated no uptake or elimination, survival could still occur, indicating that neovascularization need not be complete at the time of pedicle interruption.
Animals↗
Experimental studies in the survival of venous island flaps without arterial inflow.
The authors have studied the effects of various circulatory settings on flap survival. The dog model was used to study the survival of venous flaps without arterial inflow both as island and free flaps. Venous flaps were compared with arterial flaps without venous outflow and standard island flaps with arterial inflow and venous outflow. Attempts were made to study their vascular morphology and blood gas changes. The venous flaps without arterial inflow survived with normal hair growth and wound healing, as did the standard island flaps. These observations suggest that capillary diffusion can occur without the continuous flow of blood through a capillary. Several possible mechanisms to explain survival of the venous flaps without arterial inflow were discussed. These observations could be important in providing an animal model to study microcirculation and a possible new area for microsurgical transfer of a skin flap.
Animals↗
Vascular island skin-flap tolerance to warm ischemia: an analysis by perfusion fluorometry.
Fiberoptic perfusion fluorometry and assessment of ultimate viability were used to analyze the tolerance to warm ischemia of rat vascular island skin flaps. Both acute flaps and flaps raised 24 hours previously and then reraised were subjected to 0 (control), 6, 8, 10, and 12 hours of vascular pedicle clamping. Following clamp release, serial fluorometry documented the progressive delay in effective reflow resulting from extended periods of ischemia. Fluorometry, furthermore , suggested that flaps constructed 24 hours previously had an improved hemodynamic status with a significantly reduced period of poor reflow following clamp release. The improved hemodynamics were associated with increased viability, confirming the increased tolerance of 24-hour-old flaps to warm ischemia.
Animals↗
An improved one-stage total ear reconstruction procedure.
Based on anatomic studies of the postauricular cutaneous circulation, a modified single-stage total ear reconstruction procedure has been presented. The operation consists of using a large, superthin, well-vascularized, and well-innervated skin flap to cover the anterior surface of the auricular framework carved from costal cartilage, the posterior surface of which is covered by a subcutaneous tissue flap and then skin grafted. Improvements in the makeup and carving of the framework have been made and described. This method has been used to treat 15 cases of anotia, all with satisfactory results.
Cartilage, Articular↗
Anal reconstruction by a modified Pickrell procedure.
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Anal Canal↗
Treatment of blepharoptosis. Direct transplantation of the frontalis muscle to the upper eyelid.
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Blepharoptosis↗
Repair of large mandibular defects with vascularized rib grafts.
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Adult↗
The screening of beta-lactamase inhibitors: inhibition by fatty acids produced by bacteria.
An active principle inhibiting beta-lactamases, which was found in the culture of a bacillus strain was a mixture of known C14-C17 fatty acids. The mixture was separated into five components by high-performance liquid chromatography. Among these components, 12-methyltetradecanoic acid showed the strongest activity (I50: 20-146 microM). The anteiso fatty acids having the 1-methylpropyl group exhibited an interesting activity inhibiting beta-lactamases.
Bacillus↗
Procaspase-3 enhances the in vitro effect of cytosine deaminase-thymidine kinase disuicide gene therapy on human ovarian cancer.
Because the efficacy of genetic prodrug activation therapy (GPAT) using herpes simplex virus thymidine kinase (tk)/ganciclovir (GCV) or Escherichia coli cytosine deaminase (cd)/5-fluorocytosine (5-FC) is not satisfied in early clinical trials and the mechanism of both the GPATs have been shown to lead to the activation of cell apoptotic pathway, we hypothesized that coexpression of procaspase-3, a central downstream executioner of apoptotic pathways, with cd-tk gene leads to enhanced cell death in ovarian cancer cells in vitro. Following transfection with the vectors encoding cd and tk, 5-FC and GCV treatments lead to greater cell death in procaspase-3-expressing clones of 3AO (3AO-caspase-3) than control cells (3AO-pcDNA3), as well as more rapid activation of caspase-3 and more rapid cleavage of poly (adenosine diphosphate-ribose) polymerase (PARP). There is a greater degree of cell apoptotic rate in the procaspase-3-expressing clones than in control cells following the treatment with cd-tk/5-FC + GCV, and apoptosis is the main cell death form. None of these effects is seen following transfection with a control vector that does not encode tk and cd (pBTdel-279). The results strongly suggest that coexpression of procaspase-3 may lead to a significant enhancement of the efficacy of cd-tk/5-FC + GCV, and this strategy would be a novel and promising approach for the treatment of ovarian cancer.
Apoptosis↗
[125I]iodomelatonin-binding sites in the chicken kidney: characterization and comparison to other avian species.
The existence of [125I]iodomelatonin-binding sites in the kidney of the chicken and other avian species has been demonstrated in the present study. [125I]Iodomelatonin-binding sites in membrane preparations of the chicken kidney were reversible, saturable, specific and of high affinity. Scatchard analysis of the specific binding revealed an equilibrium binding constant (Kd) of 30.3 +/- 5.1 pmol/l (n = 5) and a total number of binding sites (Bmax) of 2.89 +/- 0.24 fmol/mg protein (n = 5) at the middle of the light period (mid-light). The Hill coefficient approached 1.0, suggesting a single class of [125I]iodomelatonin-binding sites in the chicken kidney. The diurnal variation study showed that the Bmax was 52% higher at mid-light than that in the middle of dark period (1.90 +/- 0.33 fmol/mg protein, n = 4; p < 0.05), with no significant variation in Kd. The Kd value determined from kinetic analysis was 10.8 pmol/l in the mid-light birds, which was comparable to values determined from equilibrium studies. The competition inhibitor experiments demonstrated that [125I]iodomelatonin-binding sites were highly specific for melatonin with the following order of potency: 2-iodomelatonin > melatonin, 6-chloromelatonin > 6-hydroxymelatonin N-acetylserotonin >> 5-methoxytryptamine, 5-methoxytryptophol, 5-hydroxyindole-3-acetic acid, 5-hydroxytryptamine, 1-acetylindole-3-carboxaldehyde, 3-acetylindole, tryptamine, 5-methoxyindole-3-acetic acid, L-tryptophan, harmaline, acetylcholine, epinephrine and norepinephrine. Studies on the relative binding density of [125I]iodomelatonin to the kidney in different species of birds showed the following descending order: duck > chicken > pigeon > quail.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Effects of guanosine 5'-O-(3-thiotriphosphate) on 2-[125I]iodomelatonin binding in the chicken lung, brain and kidney: hypothesis of different subtypes of high affinity melatonin receptors.
Effects of 10 mumol/l guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S), a non-hydrolyzable analog of guanosine 5'-triphosphate, on 2-[125I]iodomelatonin binding were investigated. In the chicken lung, 10 mumol/l GTP gamma S significantly increased (p < 0.05) the equilibrium dissociation constant (Kd) values, but did not affect the maximum number of binding sites (Bmax). Conversely, in the chicken brain, GTP gamma S significantly depressed (p < 0.05) the Bmax, but did not change the Kd of the 2-[125I]iodomelatonin binding sites in the brain tissue. A third variation was observed in the chicken kidney with GTP gamma S altering (p < 0.05) both the Kd and the Bmax of 2-[125I]iodomelatonin binding sites. The reason underlying the different effects of GTP gamma S on 2-[125I]iodomelatonin binding in the tissue preparations is not clear. However, we would like to hypothesize that they may represent distinct subtypes of the ML-1-type melatonin receptor with different receptor-G-proteins-effector complex. The group represented by the 2-[125I]iodomelatonin binding sites found in the chicken lung, which is downregulated by GTP gamma S with a consequent increase in the Kd value, has been designated ML-1 alpha. The second group, exemplified by the brain 2-[125I]iodomelatonin binding sites, which respond to GTP gamma S with a change in Bmax, has been labelled ML-1 beta. The third group, characterized by GTP gamma S-mediated alterations in both Bmax and Kd and found in the chicken kidney, has been called ML-1 gamma. Different subtypes of melatonin receptors may address the issue of the different physiological actions of melatonin reported in individual tissues within the same species or similar tissues but different species. Specialized responses could be generated depending on the predominant subtype of ML-1 receptors associated with the target tissue.
Animals↗
Melatonin implant decreases the density of 2[125I]iodomelatonin binding sites in the chicken spleen.
Changes in 2[125I]iodomelatonin binding to the chicken spleen following disruption of the normal melatonin rhythm by a slow-release melatonin implant were investigated. Melatonin capsules were implanted in 6-week-old male and female chickens reared under 12 h light/12 h darkness. The mid-light and mid-dark serum melatonin was measured throughout the period of implantation. Spleen weight and characteristics of splenic 2[125I]iodomelatonin binding sites were studied during the mid-light at 4 or 8 weeks after implantation. Melatonin implantation disrupted the normal diurnal rhythm of serum melatonin and elevated the mid-light level to the control mid-dark value until 5 weeks after implantation. The melatonin implant caused a significant decrease in the density of 2[125I]iodomelatonin binding sites at 4 weeks after implantation while there were no significant changes in the binding affinity. The reduction in 2[125I]iodomelatonin binding may be a result of down-regulation of the melatonin receptors by elevated serum melatonin. Alternatively, it may be due to an indirect suppression of 2[125I]iodomelatonin binding sites by the elevated sex hormones since melatonin implants increased the levels of testosterone in the male and estradiol in the female. Implantation of melatonin capsules significantly increased the body and spleen weights in the male chicken. These weight changes may be partly explained by the anabolic and erythropoietic action of the increased circulating testosterone.
Animals↗
Comparison of serum hepatitis B virus replication markers in patients with chronic hepatitis B: studies on HBeAg/anti-HBe system, viral DNA polymerase and HBV-DNA.
The detection of HBV-DNA in serum by molecular hybridization is the most sensitive and specific marker or replication and infectivity of hepatitis B virus and currently is proposed as a routine diagnostic technique in the follow-up of HBV-related diseases. Comparing different techniques already described, we found that direct spotting of serum samples on nitrocellulose membranes under vacuum filtration, followed by denaturing and neutralizing washes is more practical, simple, sensible and reproducible. DNA polymerase assay using phosphonoformic acid as specific viral inhibitor has shown 86.8% of concordance with HBV-DNA detection, and so, it is an useful alternative in the follow-up of hepatitis B chronic patients. We found 19.2% HBeAg positive samples with no other markers of viral replication and no anti-HBe positive sample had detectable HBV-DNA. Discordance between the 2 systems have been extensively described, and we confirm this for the first time in our country. Molecular biological techniques are essential to determine the replication status of chronic hepatitis B patients.
DNA, Viral↗
Lead and zinc removal by laboratory-scale constructed wetlands.
Constructed wetlands have the potential to trap and remove metals in mine wastewater. To determine the effectiveness of constructed wetlands for treating selected heavy metals in neutral mine effluent typical of lead mines, eight laboratory-scale constructed wetlands were set up to treat a synthetic, slightly alkaline, mine water containing 34.2 mg/L sulfate (SO4(2-)), 50 micrograms/L lead (Pb), and 300 micrograms/L zinc (Zn). After 45 days, one of the wetlands was switched to treat a synthetic smelter effluent with a much greater load of SO4(2-), sodium (Na+), and Pb. Temperature, hydraulic loading, and substrate composition typically did not affect treatment efficiency. The pH of the effluent was reduced from 8.0 to 8.5 to near neutral. The average removal in the eight wetlands was 90% for Pb and 72% for Zn. In wetlands operating on synthetic mine water, SO4(2-) was completely removed, likely by conversion to sulfide by sulfate-reducing bacteria. In the wetland operating on synthetic smelter effluent, only approximately 25% of 6 g/L influent sulfate was removed, and a breakthrough period of 4 days for Na+ was observed. Whole effluent toxicity assays on undiluted wetland effluent from wetlands treating mine and smelter water had 100% survival of fathead minnows and Daphnia magnia. Survival of Ceriodaphnia dubia was zero in undiluted effluent, but 75 to 100% survival was observed when the effluent was diluted to one-half strength.
Animals↗